1. Field of the Invention
The present invention relates to a current source, electronic apparatus, and an integrated circuit each employing a PLL (phase-locked loop) circuit.
2. Description of the Related Art
Japanese Patent Laid-open No. Hei 4-215317 (hereinafter, Patent Document 1) discloses a phase-locked loop circuit.
In the PLL circuit as the phase-locked loop circuit of Patent Document 1, a pair of voltages is generated by a voltage-current converter in a voltage control oscillator in the control loop, and this pair of voltages is input to transistors for the constant current source in a charge pump.
This eliminates the need for the phase-locked loop circuit of Patent Document 1 to have an external power supply for allowing the constant current operation of the transistors for the constant current source in the charge pump.